• Lightly grease a 23cm springform tin.
• Crush the biscuits in a bag with a rolling pin or use a food processor. Melt the butter and mix in the biscuit crumbs. Tip into the cake tin and press down firmly making an even layer. Chill until set.
• Place the cream cheese, cream, creme fraiche and vanilla extract in a bowl and whisk until stiff peaks form. Add the sugar and mix thoroughly. Spoon on top of the biscuit base and spread level. Cover and chill for at least 2 hours.

Blackcurrant Topping

• Place the blackcurrants in a saucepan with the water and sugar and gently heat until the sugar dissolves and the juices run. Cook for about 3 minutes.
• Mix the cornflour with a little water to form a paste and add to the saucepan. Cook gently until the juices start to thicken. Remove from heat and cool completely.
• Remove the cheesecake from the tin and transfer it to a serving plate. Spoon the blackcurrant mixture on top. Cut and serve.